

var num=0;

var pedometer=document.getElementById('pedometer');

if (window.DeviceMotionEvent) { 
                 window.addEventListener('devicemotion',deviceMotionHandler, false);  
        } 
//      var speed = 10;//speed
//      var x = y = z = lastX = lastY = lastZ = 0;
//      function deviceMotionHandler(eventData) {  
//        var acceleration =eventData.accelerationIncludingGravity;
//              x = acceleration.x;
//              y = acceleration.y;
//              z = acceleration.z;
//              if(Math.abs(x-lastX) > speed || Math.abs(y-lastY) > speed || Math.abs(z-lastZ) > speed) {
//                  //简单的摇一摇触发代码
//                  num++;
// 					pedometer.innerText="步数："+num;
//                  
//              }
//              lastX = x;
//              lastY = y;
//              lastZ = z;
//      }
 var SHAKE_THRESHOLD = 800;  
    var last_update = 0;  
    var x, y, z, last_x, last_y, last_z;  
       
    function deviceMotionHandler(eventData) {  
        
      var acceleration =eventData.accelerationIncludingGravity;  
      //alert(newDate().getTime());
      var curTime = new Date().getTime();  
       
         // alert(curTime - last_update);
      if ((curTime - last_update)> 300) {  
                
          var diffTime = curTime -last_update;  
          last_update = curTime;  
       
          x = acceleration.x;  
          y = acceleration.y;  
          z = acceleration.z;  
       
          var speed = Math.abs(x +y + z - last_x - last_y - last_z) / diffTime * 25000;  
          
               if (speed > SHAKE_THRESHOLD) {  
                    num++;
   					pedometer.innerText="步数："+num;
          }  
          
          last_x = x;  
          last_y = y;  
          last_z = z;  
        }  
    }  

    
    
